Add or Subtract Days from a Date

What it does

Month and year arithmetic is clamped to the end of the month, so 31 January plus one month is 28 or 29 February, as most contracts and banks calculate it.

How to use it

1. Choose a start date.
2. Enter a positive or negative amount and a unit.
3. Read the resulting date and weekday.

Example

31 January 2026 plus one month is 28 February 2026. Select Try an example above to see it.

When it helps

• Payment terms such as net 30.
• Visa and notice period deadlines.
• 90 day return windows.

Questions